Rotary engine.



No. 787,762. PATENTED APR. 18, 1905.

' G. A. & 0. W. HULT.

ROTARY ENGINE.

APPLIOATION FILED SEPT. 22, 1904.

' 2 SHEETS-SHEET 1.

IXR-bncmea Smucw toms.

UNITED STATES Patented April 18, 1905.

PATENT OFFICE.

CARL ALRIK HULT AND OSCAR WALFRID HULT, OF STOCKHOLM, SWEDEN.

ROTARY ENGINE.

SPECIFICATION forming part of Letters Patent No. 787,762, dated April18, 1905.

Application filed September 22, 19Q4. Serial No. 225,522.

T0 (11 whom it fluty concern:

Be it known that we, CARL ALRIK Horn: and OSCAR VALFRID HULT, subjectsof the King of Sweden and Norway, and residents of Inedalsgatan 1,Stockholm, in the Kingdom of Sweden, have invented certain new anduseful 1mprovements in Rotary Engines, Pumps, and the Like, of which thefollowing is a specification, reference being had therein to theaccompanying drawings. 7

This invention relates to rotary engines, pumps, or the like of thatclass in which the casing or cylinder for reducing the friction betweenthe same and the piston drum or roller mounted eccentric in the saidcasing and rotating in contact with the inner surface of the same ismade rotatable, so that it is caused to rotate under the action of thedrum. In such engines, &c., as hitherto constructed the periphery of thedrum and the inner cylindrical surface of the casing or cylinder have.

the same speed; but in consequence of the eccentricity and the fact thatthe end walls of the cylinder are fixed to the cylinder, andconsequently have to make the same number of revolutions as the latter,the said end walls will have a speed different from that of the endsurfaces of the piston. The said difference in the speeds of the endsurfaces of the drum and the end walls of the cylinder is comparativelygreater near the center of the drum and decreases toward its periphery.There is also at the said periphery a difference in the speeds of thedrum ends and the said end walls, and between the speed of the ends ofthe pistons rotating in contact with the end walls and the speed of thesaid walls there is a difference which is greater. The greater portionof the piston extends beyond the periphcry of the drum. The saiddifferences in speed or the relative movement of the drum end and theends of the pistons, on the one hand, and the end walls of the cylinder,on the other hand are very disadvantageous to the durability of theengine as well as to the tightness between the bearing-surfaces of theparts, as the said surfaces must fit air-tight, the sliding pistons andthe slots provided for the samein the drum making the arrangement ofsuitable tightening means in the ends of the drum impossible. Nor in theend walls of the cylinder in machines constructed as stated abovetightening meansas, for instance, tightening-rings can be provided, assuch means, owing to the eccentricity of the drum and the end walls ofthe cylinder, would have a position eccentric to the drum, andconsequently would be of very little or no use. For the said reasons theengines must be so arranged that the ends of the drum and the pistonsfit as good as air-tight between the end walls ofthe cylinder, asmentioned above, in order that not too great a quantity of motive fluidmay leave the engine between the bearing-surfaces of the said parts. Thesaid arrangement may certainly be made without causing too great afriction, as the end Walls of the cylinder partake in the rotation; butat the slightest variations in the temperature the drum and its pistonsusually will have a higher temperature than the. cylinder, which resultsin the drum and the pistons being locked between the said end walls ortheir running with such a great friction against the said walls that agreat part of the force is lost in spite of the mutual rotating movementof the parts, which isnormally also the case, but in smaller extent, ifthe said bearing-surfaces fit sufliciently close not to permit leakage.It has even happened that the sliding pistons in machines of theconstruction stated above have been so firmly locked between the endwalls of the cylinder that they have been broken.

This invention has for its chief object to remove the saiddisadvantages, which is gained by arranging the casing or cylinder ofthe engine, &c., as a ring free from the end walls and caused to partakein the rotation of the drum only by the friction against the same andthe end walls, which are fixed to or made integral with the drum, asclearly stated below with reference to the accompanying drawings, inwhich 7 Figure 1 is a transverse vertical section view of an enginearranged in accordance with our invention, and Fig. 2 is a longitudinalvertical sectional view of the same engine.

In the said figures, l is the frame of the engine. 2 is the shaftjournaled in roller-bearings 3, arranged in the end pieces or covers 4of the said frame. The shaft 2 has a longitudinal bore 5, in which isloosely mounted a pipe 6, fixed to the frame and communicating with theinlet-pipe 7 for the motive fluid.

8 is the piston-drum of the engine, fixed on the shaft 2 or madeintegral with the same. The said piston has a channel 9, communicatingwith a port 10 in the shaft 2. Also in the pipe 6 a port 11 is provided,said ports 10 and 11 being so located that they correspond once duringone revolution of the shaft and the drum, thus permitting motive fluidto pass into the engine to exert its force against the right-hand sideof the piston 12, Fig. 1, sliding in a radial slot 13 in the drum, andso cause the drum and the shaft to rotate. During the rotation of thedrum the said piston is pressed by the centrifugal force against theinner wall of the casing or cylinder of the engine. According to ourinvention the said casing or cylinder consists of a ring 14, which isfree from the end walls 15 15 of the casing, Fig. 2. One of the said endwalls is made integral with the piston 8 and the other wall is fixed tothe same. Thesaid ring 14 is supported by rollers 16 16, journaled onball or roller bearings 17, and is caused to rotate with the drum by thefriction between the ring and the end walls 15 15 and the frictionbetween the ring and the drum which bears upon the inner side of thering, as shown in Fig. 1. The said ring 14 is made in two parts topermit the mounting of a ring 18, of steel. After the said rings areplaced on the drum they are held in position by the end walls 15 15, oneof which is pressed against the drum and fixed to the same and the shaft2 by means of a nut 19, screwed on the shaft, Fig. 2. In the ends of thering 14 recesses 20 are provided, in which packing-rings 21 of suitablematerial are mounted, pressed against the inner side of the end Walls 1515 by means of springs 22 or the like, mounted in the said recesses,Fig. 2. In the inner sides of the end walls 15 15 grooves 23 areprovided, Fig. 2, serving as guideways for the ends of the pistons 12.In Fig. 2 a portion of the piston 12 is broken away in order that one ofthe said grooves 23 may be visible.

24 is an eduction-port for the exhaust fluid.

As easily understood from the above, motive fluid is admitted in theright chamber 25 of the engine each time the port 10 coincides with theport 11 of the pipe 6, which fluid presses against the piston 12 untilthe latter I has reached the contact-point between the drum and thecylinder and the eduction-port 24 has passed by the said point. The drum8 will then continue in its rotation, owing to the inertia of the parts,and motive fluid is thereupon again admitted in the chamber 25, and. soon. By the said provision of grooves 23, which is possible through theconnection of the end walls with the drum, the piston is suitablysupported when projecting from the drum, thus being not liable to bebroken off when acted upon by the fluid-pressure at the right-hand side,Fig. 1.

According to our invention the piston is composed by two or more plates,Fig. 1, free from each other and mounted at the side of each other, eachbearing against the inner side of the ring 14 and tightening against thesame. By the said arrangement of the piston its outer edge will adjustitself transversely to the inner side of the ring at every position ofthe piston, and thus fit closely to the ring.

As seen from the above, there is not relative movement between the drumwith its piston and the end walls of the cylinder, said relativemovement or difference in motion existing now at the bearing-surfaces ofthe ring and the end walls connected with the drum. At the saidbearing-surfaces suitable tightening means as, for instance,tightening-rings, as shown in the drawings-can easily be provided, theclose fitting of the surfaces moving in relation to each other, which isnecessary in the engines as hitherto constructed, being thus notnecessary in engines arranged in accordance with our invention. Thus thegreatest part of the friction between the surfaces movable to each otherin engines of the old construction will obviously be removed by ourinvention, as the bearing-surfaces in our engines are yielding. At thesame time the difference in the speeds of the said surfaces is reduced,owing to the fact that the relative movement now exists between partssituated ,nearer the periphery of the casing.

By our invention the construction of the whole engine will beconsiderably simplified, especially when composed of two or morecylinders with pist'on-drums-as, for instance, in compound or tripleengines-in which case the piston-drum is provided with partitionwalls insuitable distances from each other and arranged in such a manner thatbetween each two walls a cylinder-ring can be mounted, the engine beingthus divided into working chambers which can be properly adapted to thedifferent degrees of expansion. Owing to the fact that by the saidarrangement each cylinder-ring can rotate independent of the other ringor rings, the said rings as well as the corresponding piston-drums mayhave different diameters, so that the length of the piston stroke or theworking chamber can be increased in proportion to the necessary aug:mentation of the volume of the successive working chambers. By this theessential advantage is gained that the proportion between the length,width, and depth of all working chambers can be maintained, so that thevolume necessary for each working chamber can be obtained with a minimumof area of the walls inclosing the said chamber, the con ditions mostsuitable for the slightest possi ble cooling of the motive-fluid steambeing thus created. The said arrangements of the working chambers wouldhardly be possible if the different chambers in a compound engine, forinstance, be provided within a single cylinder by dividing the same intocompartments by means of a partition-wall and by mounting twopiston-drums on the shaft.

With regard to the practical execution the diameters of the two workingchambers must be the same, in consequence whereof the difference betweenthe volumes of the high-pressure chamber and the low-pressure chambercan be effected only by giving the said chambers different widthlongitudinally to the shaft.

In the drawings only one sliding piston is shown, but obviously two ormore pistons may be employed. The motive fluid may consist of steam orother suitable elastic fluid. In applying our invention tointernal-combustion engines the compression and working chambers mayeach be provided in the same easy manner as stated above with relationto compound and similar engines. In both cases the advantage is gainedthat each cylinderring rotates between its corresponding end wallsindependent of the adjacent ones, in consequence whereof it may beguided in a position most suitable for an easy running and the slightestpossible wear of the partsz'. 0., without being subjected to anyunfavorable pressure from or acted upon by the end walls. Our inventionmay obviously be applied to pumps and similar apparatus. In thepractical execution of our invention the arrangements shown in thedrawings may be moditied in many respects without exceeding the limitsof the invention defined in the claims.

Having now described our invention, what we claim as new, and desire tosecure by Letters Patent, is

1. In rotary engines, pumps and the like the combination of a rotatingcylinder, consisting of a ring which is free from the end walls of thecylinder, a piston-drum mounted eccentric in the said cylinder, and theend walls of the cylinder forming end pieces on the said drum andfitting against the ends of the said ring, substantially as describedand for the purpose set forth.

2. In rotary engines, pumps and the like the combination of a rotatingcylinder, consisting of a ring which is free from the end Walls of thecylinder, a piston-drum mounted eccentric in the said cylinder, the endwalls of the cylinder forming end pieces on the said drum and fittingagainst the ends of the said ring, one or more tightening-rings in theend surfaces of the cylinder-ring and means for pressing saidtightening-rings against the end walls of the cylinder, substantially asdescribed and for the purpose set forth.

3. In rotary engines, pumps and the like the combination of a rotatingcylinder, consisting of a ring which is free from the end walls of thecylinder, a piston-drum mounted eccentric in the said cylinder, the endwalls of the cylinder forming end pieces on the said drum and fittingagainst the ends of the said ring, one or more tightening-rings in theend surfaces of the cylinder-ring, the sliding piston or pistons of thedrum, said pistons consisting of plates independent of each other andmounted at the side of each other, and grooves provided in the said endpieces of the drum and guiding the saidpiston or pistons, substantiallyas described and for the purpose set forth.

, In witness whereof we have hereunto signed our names, this 6th day ofSeptember, 1904, in the presence of two subscribing witnesses.

CARL ALRIK HULT. OSCAR WALFRID HULT.

Witnesses ERNST SvAN vIs'r, ROBERT APELGREN.

